Well this Mike Hopkins guy is mostly comparing neutron yields from the D-T reaction LPP were testing with. Lerner inevitably wants to use the p-B reaction which produces no neutrons (aside from residual gas sources), however to test his pinch device using D-T is much easier as the fusion temperature is lower. It also makes for a good comparison to other pinch devices. Since the p-B reaction yields mostly photons they seek to make a fusion device from the charged particles (a stream of electrons and ions) and the photon energy collected via photoelectric current. Some of those gammas are uncapturable but the energy still captured is supposedly a net gain once they can get a high enough plasma temperature.
Engineering the Photon Capture Sphere Thing (PCST) to capture photons and electrons while not activating all the material with a 100-year half-life used in its construction, nor having it rip itself apart from dissimilar metals and thermal gradients, not having an unacceptably high rate of particles sputter the crap out of inside, is all non-trivial and would require significant trial-and-error builds. This is of course assuming they manage to make a working p-B reaction with their pinch. Best of luck to Lerner, but I'm not counting on seeing any significant results unless some billionaire type takes a risk on him.